Hitherto, there has been provided a pump such as a uniaxial eccentric screw pump as disclosed in Patent Literature 1 (JP 2008-175199 A). The uniaxial eccentric screw pump is capable of force-feeding a fluid having a high viscosity, such as starch syrup, a fluid that is prone to alteration and is required to be handled carefully, a fluid containing a solid, fibers, air bubbles, as well as a fluid having a low viscosity, such as a liquid. Therefore, the uniaxial eccentric screw pump can also be used suitably for force-feeding food and the like.
Here, the above-mentioned uniaxial eccentric screw pump exerts a pump action through rotation of a male-screw-shaped rotor in a stator having a female-screw-shaped insertion hole. Further, as in the case of the stator in the uniaxial eccentric screw pump, a sliding member configured to slide while being in contact with another member (rotor in the uniaxial eccentric screw pump) along with operation of the pump may be arranged so as to be exposed to a flow path through which a fluid to be force-fed flows. Therefore, when a pump such as a uniaxial eccentric screw pump is used in an unintended usage form to apply an excessive load to the stator and the rotor, there is a risk in that a wear substance and a flake of the sliding member may be generated and mixed in the fluid.
Therefore, there is a demand for providing a sliding member for pump in which even the use of the sliding member in such a state that a wear substance and the like are generated, as described above, can be quickly and accurately grasped, and for providing a pump operation state detection system including the sliding member. In particular, in a pump capable of force-feeding food and the like as in the above-mentioned uniaxial eccentric screw pump, there is a strong demand for quickly and accurately detecting the mixing of a wear substance and the like in the fluid.
In view of the foregoing, it is an object of the present invention to provide a sliding member in which generation of a wear substance and the like can be quickly and accurately grasped even if the wear substance and the like are generated when the sliding member slides while being in contact with another member, and to provide a pump operation state detection system for a pump using the sliding member.